Faculty Bibliography

The management of acetabular bone loss during revision arthroplasty is a challenging problem. Not only are there a wide variety of potential defects, but the location of these defects can also drastically change the hip center of rotation, stability, and biomechanics. First, the assessment of the severity and location of bone loss preoperatively is highlighted as it is imperative to evaluate the acetabular bone stock remaining. It is especially important to determine how to identify a pelvic discontinuity. Various classification systems are discussed to help surgeons adequately assess and evaluate these defects. There are also numerous implants and treatment strategies available to manage the problem, all of which are determined by that preoperative assessment and classification. We review the history of managing these defects and how management has evolved into modern designs, including but not limited to structural allograft, distraction arthroplasty, jumbo cups, metal augments, cup-cages, and custom triflanges. This review then describes the up-to-date clinical results of these various techniques, highlighting the surgical execution needed to obtain a successful result. By describing the preoperative assessment, the acetabular defect classifications, and proposed evidence-based treatment algorithms, we hope that this review will enhance the understanding of these challenging reconstructions in the setting of acetabular bone defects.

Total joint arthroplasty relies on the use of biomaterials that are biologically inert and capable of forming wear-resistant articulating surfaces. Polyethylene use in arthroplasty has become ubiquitous since its introduction in the 1960s. Early arthroplasty procedures of the hip utilized poly-tetra-flouroethylene, or "Teflon," due to its low coefficient of friction that was presumed to closely mimic the hyaline cartilage of native joints. Early catastrophic wear of Teflon caused a significant local tissue reaction contributing to osteolysis, aseptic loosening, and clinical failure ultimately limiting the material's surgical utility. Advancements in biomaterial synthesis and processing led to the fortuitous discovery of ultra-high-molecular-weight-polyethylene (UHMWPE) and the eventual evolution to highly cross-linked polyethylene (HXLPE) as a bearing surface in hip arthroplasties with robust, long-term clinical success. Ultra-high-molecularweight-polyethylene was readily adopted for use in total knee arthroplasty following the material's successful use in hip replacement, however, the unique biomechanics of the knee have posed unique challenges. The use of HXLPE in knee arthroplasty has increased, however, clear data regarding its benefit over UHMWPE are conflicting. Recently, clinical as well as research and development studies of UHMWPE and HXLPE have focused on alternative postprocessing methods to optimize material stability and wear resistance. Second generation HXLPE utilizing sequential annealing processes or vitamin E to stabilize free radicals are promising means to improve mechanical stability and wear resistance for use in joint arthroplasty, however, more data is required to evaluate long-term outcomes and cost-effectiveness. In this review, we discuss the history and innovation of polyethylene use in orthopedic surgery and evaluate the current literature on outcomes of polyethylene use in hip and knee replacement.

BACKGROUND:Concerns regarding the effects of dexamethasone on diabetics' glucose control have stymied its use following total joint arthroplasty. This study aimed to evaluate the effects of 2 intravenous (IV) perioperative doses of dexamethasone on glucose levels, pain scores, and inpatient opioid consumption following total joint arthroplasty in diabetic patients. METHODS:A retrospective review of 523 diabetic patients who underwent primary elective THA and 953 diabetic patients who underwent primary elective total knee arthroplasty (TKA) between May 6, 2020, and December 17, 2021 was conducted. Patients who received 1 dose (1D) of perioperative dexamethasone 10 mg IV were compared to patients who received 2 doses (2D). Primary outcomes included postoperative glucose levels, opioid consumption as morphine milligram equivalences, postoperative pain as Verbal Rating Scale pain scores, and postoperative complications. RESULTS:The 2D TKA cohort had significantly greater average and maximum blood glucose levels from 24 to 60 hours compared to the 1D TKA cohort. The 2D THA cohort had significantly greater average blood glucose levels at 24 to 36 hours compared to the 1D THA cohort. However, the 2D TKA group had significantly reduced opioid consumption from 24 to 72 hours and reduced total consumption compared to the 1D TKA group. Verbal Rating Scale pain scores did not differ between cohorts for both TKA and THA at any interval. CONCLUSION/CONCLUSIONS:Administration of a second perioperative dose of dexamethasone was associated with increased postoperative blood glucose levels. However, the observed effect on glucose control may not outweigh the clinical benefits of a second perioperative dose of glucocorticoids.

INTRODUCTION/BACKGROUND:Infection after total knee arthroplasty (TKA) impacts the patient, surgeon, and healthcare system significantly. Surgeons routinely use antibiotic-loaded bone cement (ALBC) in attempts to mitigate infection; however, little evidence supports the efficacy of ALBC in reducing infection rates compared to non-antibiotic-loaded bone cement (non-ALBC) in primary TKA. Our study compares infection rates of patients undergoing TKA with ALBC to those with non-ALBC to assess its efficacy in primary TKA. METHODS:A retrospective review of all primary, elective, cemented TKA patients over the age of 18 between 2011 and 2020 was conducted at an orthopedic specialty hospital. Patients were stratified into two cohorts based on cement type: ALBC (loaded with gentamicin or tobramycin) or non-ALBC. Baseline characteristics and infection rates determined by MSIS criteria were collected. Multilinear and multivariate logistic regressions were performed to limit significant differences in demographics. Independent samples t test and chi-squared test were used to compare means and proportions, respectively, between the two cohorts. RESULTS:) and Charlson Comorbidity Index values (4.51 ± 2.15 vs. 4.04 ± 1.92) were more likely to receive ALBC. The infection rate in the non-ALBC was 0.8% (63/7,980), while the rate in the ALBC was 0.5% (7/1,386). After adjusting for confounders, the difference in rates was not significant between the two groups (OR [95% CI]: 1.53 [0.69-3.38], p = 0.298). Furthermore, a sub-analysis comparing the infection rates within various demographic categories also showed no significant differences between the two groups. CONCLUSION/CONCLUSIONS:Compared to non-ALBC, the overall infection rate in primary TKA was slightly lower when using ALBC; however, the difference was not statistically significant. When stratifying by comorbidity, use of ALBC still showed no statistical significance in reducing the risk of periprosthetic joint infection. Therefore, the advantage of antibiotics in bone cement to prevent infection in primary TKA is not yet elucidated. Further prospective, multicenter studies regarding the clinical benefits of antibiotic use in bone cement for primary TKA are warranted.

INTRODUCTION/BACKGROUND:Selective use of dual mobility (DM) implants in total hip arthroplasty (THA) patients at high dislocation risk has been proposed. However, evidence-based utilization thresholds have not been defined. We explored whether surgeon-specific rates of DM utilization correlate with rates of readmission and reoperation for dislocation. METHODS:We retrospectively reviewed 14,818 primary THA procedures performed at a single institution between 2011 and 2021, including 14,310 FB and 508 DM implant constructs. Outcomes including 90-day readmissions and reoperations were compared between patients who had fixed-bearing (FB) and DM implants. Cases were then stratified into three groups based on the attending surgeon's rate of DM utilization (≤1, 1 to 10, or >10%) and outcomes were compared. RESULTS:There were no differences in 90-day outcomes between FB and DM implant groups. Surgeon frequency of DM utilization ranged from 0 to 43%. There were 48 surgeons (73%) who used DM in ≤ 1% of cases, 11 (17%) in 1 to 10% of cases, and 7 (10%) in >10% of cases. The 90-day rates of readmission (7.3 vs 7.6 vs 7.2%, P=0.7) and reoperation (3.4 vs 3.9 vs 3.8%, P=0.3), as well as readmission for instability (0.5 vs 0.6 vs 0.8%, P=0.2) and reoperation for instability (0.5 vs 0.5 vs 0.8%, P=0.6), did not statistically differ between cohorts. CONCLUSION/CONCLUSIONS:Selective DM utilization did not reduce 90-day readmissions or reoperations following primary THA. Other dislocation-mitigation strategies (i.e., surgical approach, computer navigation, robotic assistance, and large diameter fixed-bearings) may have masked any benefits of selective DM use.

BACKGROUND:Indications for surgery may impact resource utilization in aseptic revision total knee arthroplasty (rTKA), and understanding these relationships would facilitate risk-stratification preoperatively. The purpose of this study was to investigate the impact of rTKA indications on readmission, reoperation, length of stay (LOS), and cost. METHODS:We reviewed all 962 patients who underwent aseptic rTKA at an academic orthopedic specialty hospital between June 2011-April 2020 with at least 90 days of follow-up. Patients were categorized based on their indication for aseptic rTKA as listed in the operative report. Demographics, surgical factors, LOS, readmission, reoperation and cost were compared between cohorts. RESULTS:There were significant differences in operative time among cohorts (p < 0.001), highest among the periprosthetic fracture group (164.2 ± 59.8 min). Reoperation rate was greatest in the extensor mechanism disruption cohort (50.0 %, p = 0.009). Total cost differed significantly among groups (p < 0.001), which was highest among the implant failure cohort (134.6 % of mean) and lowest for component malpositioning cohort (90.2 % of mean). Similarly, there were significant differences in direct cost (p < 0.001) which was highest in the periprosthetic fracture cohort (138.5 % of mean), and lowest in the implant failure cohort (90.5 % of mean). There were no differences in discharge disposition, or number of re-revisions among all groups. CONCLUSIONS:Operative time, components revised, LOS, readmissions, reoperation rate, total cost and direct cost following aseptic rTKA varied significantly between different revision indications. These differences should be noted for preoperative planning, resource allocation, scheduling, and risk-stratification. LEVEL OF EVIDENCE/METHODS:III, retrospective observational analysis.

BACKGROUND:Patients undergoing total knee arthroplasty (TKA) are at increased risk of venous thromboembolism (VTE). Aspirin has been shown to be effective at reducing rates of VTE. In select patients, more potent thromboprophylaxis is indicated, which has been associated with increased rates of bleeding and wound complications. This study aimed to evaluate the effect of thromboprophylaxis choice on rates of early prosthetic joint infection (PJI) following TKA. METHODS:A review of 11,547 primary TKA patients from 2013 to 2019 at a single academic orthopaedic hospital was conducted. The primary outcome measure was PJI within 90 days of surgery as measured by Musculoskeletal Infection Society criteria. There were 59 (0.5%) patients diagnosed with early PJI. Chi-square and Welch-Two Sample t-tests were used to determine statistically significant relationships between thromboprophylaxis and demographic variables. Significance was set at p<0.05. Multivariate logistic regression adjusted for age, body mass index, sex, and Charlson comorbidity index was performed to identify and control for independent risk factors for early PJI. RESULTS:There was a statistically significant difference in the rates of early PJI between the aspirin and non-aspirin group (0.3 vs 0.8%, p<0.001). Multivariate logistic regressions revealed that patients given aspirin thromboprophylaxis had significantly lower odds of PJI (odds ratios (OR)=0.51, 95% Confidence Interval (CI) 0.29 to 0.89, p=0.019) compared to non-aspirin patients. CONCLUSIONS:The use of aspirin thromboprophylaxis following primary TKA is independently associated with a lower rate of early PJIs. Arthroplasty surgeons should consider aspirin as the gold standard thromboprophylaxis in all patients in which it is deemed medically appropriate and should carefully weigh the morbidity of PJI in patients when non-aspirin thromboprophylaxis is considered.

INTRODUCTION/BACKGROUND:Increasing age and hip fractures are considered risk factors for post-operative complications in total hip arthroplasty (THA). Consequently, older adults undergoing THA due to hip fracture may have different outcomes and require additional healthcare resources than younger patients. This study aimed to identify the influence of age on discharge disposition and 90-day outcomes of THA performed for hip fractures in patients ≥ 80 years to those aged < 80. MATERIALS AND METHODS/METHODS:A retrospective review of 344 patients who underwent primary THA for hip fracture from 2011 to 2021 was conducted. Patients ≥ 80 years old were propensity-matched to a control group < 80 years old. Patient demographics, length of stay (LOS), discharge disposition, and 90-day post-operative outcomes were collected and assessed using Chi-square and independent sample t tests. RESULTS:A total of 110 patients remained for matched comparison after propensity matching, and the average age in the younger cohort (YC, n = 55) was 67.69 ± 10.48, while the average age in the older cohort (OC, n = 55) was 85.12 ± 4.77 (p ≤ 0.001). Discharge disposition differed between the cohorts (p = 0.005), with the YC being more likely to be discharged home (52.7% vs. 27.3%) or to an acute rehabilitation center (23.6% vs. 16.4%) and less likely to be discharged to a skilled nursing facility (21.8% vs. 54.5%). 90-day revision (3.6% vs. 1.8%; p = 0.558), 90-day readmission (10.9% vs. 14.5%; p = 0.567), 90-day complications (p = 0.626), and 90-day mortality rates (1.8% vs 1.8%; p = 1.000) did not differ significantly between cohorts. CONCLUSION/CONCLUSIONS:While older patients were more likely to require a higher level of post-hospital care, outcomes and perioperative complication rates were not significantly different compared to a younger patient cohort. Payors need to consider patients' age in future payment models, as discharge disposition comprises a large percentage of post-discharge expenses. LEVEL OF EVIDENCE/METHODS:Level III, Retrospective Cohort Study.